new yoek



Pa tented Ja 1, 1929;

UNITEDTSTATES, PATENT ,oFFI'CE.

RALPH E. sauna, or moonr'vnnnoiv, NE

company, 01 NEW YORK, N.

W YORK, ASSIGNOR T0 METALS RECOVERY Y., A CORPORATION OF MAINE.

CONCENTBA TION OF ORES BY FROTH FLOTATION.

No Drawing.

This invention relates tothe concentration of minerals, and has for its object the pro-'v vision of certain improvements .in' the concentrationof minerals by flotation. l The invention more particularly relates to the concentration of minerals by frdth flotation.

Various organic mineral collecting'agents have been proposed for the purpose of floating' mineral particles, as distinguished from angue particles, in froth flotation processes.

hey have met with varying degrees of success in commercial practice. Some of these l agents are effective with certain ores, but-yield relatively poor results with other ores. 'In general these agents may be employed in small amounts, but their cost of manufacture is fre quently so high as to make their use .uneconomical. It is therefore seen that, even though considerable progress has beenmade in the, art of flotation agents, awide field of application remains for an agent that'is'not only relatively cheap to make, but which can be used with a greatervariety of ores'to effeet still higher recoveries of the valuable minerals.

The present invention is based on my discovery that organic selenium compounds are very effective mineral-collecting agents, particularl in the concentration of minerals by froth otation. Ihe' invention aecordin 1y comprises conducting the flotation operationin the presence of an organic selenium compound as themineral-collecting agent. Among the organic selenium compounds that lend themselves to the ractice of the invention may be mentionedSuch-compoflnds as phenylselenourea. C,H,NI-I) ,CS, l phenylselenourethane G,H .,NHGSeOC I I selenophenol (C,H .,SeH) and its homologs, particularly selenocresol C,H,CH SeH.

The-organic selenium compounds employed in the practice of the invention are essentially agents and are substanmineral-collectin thing power. In the contially devoid of centrationof minerals by froth flotation, em-

ploying such organic selenium compounds as mineral ooll j a nts, it is therefore nec- USO-8 g agent, such as pine Application filed m 11, 1928. Serial No 211,097(

oil, terpineol, cresol, 'aldol, or the like, to produce the necessary frothing action.

The organicselenium compound may be introduced into the ore or mineral pulp in any convenient manner and at any appropriate stage preceding or during the flotation operation. Thus, it may advantageously be ground with the ore, or it may be added to the comminuted ore at any stage prior to the flotation operation. The organic selenium compounds characteristic of the invention are sutficientlv soluble in water so that they maybe added tb the pulp in solid form, preferably in a relatively fine state of subdivision. In order to secure prompt dissemination throughout the mineral pulp, the organic selenium compound may be dissolved in an appropriate'solvent therefor and the resulting solution added to v the pulp. The frothing agent is preferably,

though not necessarily, added tothe mineral pulp as the pulp enters the flotation apparatus.- In certain cases it is advantageous to dissolve the organic selenium compound in the frothing agent, and then add the resultingsolution to the pulp at any appropriate stage preceding or during the flotation operation.

The quantity of the organic selenium compound to be employed in practicing theinvention depends to some extenton the ore or mineral being treated. Good results are attainedwith one pound, and less, of the organic selenium compound per ton of dry ore. In general, however, I have found that onehalf of a pound, and less, per ton of dry ore gives satisfactory results.

An y alkali, such lVhile, in practicing the invention, the orper ore, using seleno-benz-amide as the mineral collecting agent. The-amounts of reagentsspecified-ar'e in terms of pounds per ton of dry ore: v

My studies of the organic selenium compounds available for the practice! of the invention have led me to the belief. that their eii'ectiveness in froth flotation processes is in large part due to the presence in the com pound of selenium in a negative state and in a relatively low state oi valence. In these organic compounds, the selenium is present as a di-valent negative element. The mineral-collecting agents of the presentinventionare therefore characterized'by their reduced or di-valent negative selenium. In

addition, the organic selenium coi'npounds of the invention, like other organic non-oleaginous mineral-collecting agents, should impart to the mineral particle, when adsorbed or otherwise attached thereto, a wator-repellent surface. p

It is, of course, not necessary that sub stantially pure organic selenium compounds be employed in the ractice of the invention, although more uniflirm and satisfactory resuits will be attained and better control 0 the selective action of the mineral-collecting agent is possible with commercially or practically pure organic compounds of selenium. However, commercial products and crude reaction products containing substantial and eiiective amounts of one or more organic selenium compounds may be used in carrying out the invention.

It will be understood by those skilled in the art that the present invention is applica-- ble to the treatment otflotation of various kinds of mineral mixtures both natural and artificial. In the appended claims, I have accordingly employed the term mineral in a broad sense 'to include ores, mineral products and all materials-amenable to concentration or similar treatment by the flotation processes; claimz. I V 1. The improvement in the concentration of minerals by froth .flotationwhich comprises subjecting the mineral in'the form of a pulp to a froth flotation operation in the presence of it mineral-collecting agent. which -is anorganie selenium compound in which the selenium is present in a negative state.

2. The improvement in thcconcentration of minerals by both flotation which comprises subjecting the mineral in the form of a pulp to a froth flotation operation in the presence of a mineral-collecting agent which is an organicfselenium compound in which the selenium is present in a di-valent negative state.

3. The improvement in the concentration. of ninerals by froth flotation which comprises subjecting the mineral in the'form of a pulp to a froth flotationoperation in the presence of a mineral-collecting agent which 'is an organic selenium compo capable of imparting a water-repellent surface to mineral particles'and in which the selenium is present 111 a di-valent negative state.

4. The improvement in the concentrationof minerals by froth flotation which comprises subjecting the mineral in the form of a plup to a froth flotation operation in the presence of seleno-benz-amide. 5. The improvement inthe concentration of minerals by ,froth flotation which come f prises subjecting the mineral in the form of a pulp to a fiotation operation in the presence of a mineral-collecting agent which-is an organic compound containing selenium chemically combined therein.

6. The improvement in the concentration of minerals by froth flotation which comprises subjecting the mineral in the form of a pulp to a froth flotation operation in the presence of a mineral-collecting agent which is an aromatic compound containing selemum chemically combined therein. 1 I In testimony whereof I aifix my s1 gnature;

RALPH E. SAYRE. 

